US4032599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilic copolymers
Assignee: HYDRON Ltd BROADWALK HOUSE
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Filing: 1974-12-09
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Granted: 1977-06-28
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Expires: 1994-12-09
Abstract
Abstract A hydrophilic copolymer suitable for contact lenses comprises units derived from acrylic acid or methacrylic acid or from a hydrophilic monomer, such as N-vinyl 2-pyrrolidone or 4-vinyl pyridine, containing at least one heterocyclic group as a major hydrophilic unit. The copolymer preferably contains units derived from a hydrophobic monomer, such as methyl methacrylate, and it may also contain units derived from a crosslinking agent and an ethylene oxide-propylene oxide block copolymer. The copolymers are capable of absorbing large quantities of water and are particularly suitable for use in contact with living tissue.
Inventors
- 👤 Philip William Cordrey
- 👤 Wiktor Mikucki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:31
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/04; G02B1/041; G02B1/043; C; C08; C08F; C08F226/00; C08F226/06; C08F283/00; C08F283/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
166 words
A hydrophilic copolymer obtained by forming a polymerization reaction mixture consisting essentially of (A) N-vinyl-2-pyrrolidone, (B) methyl methacrylate, (C) at least one cross-linking agent having at least two olefinic double bonds in its molecule and (D) an ethylene oxide-propylene oxide block copolymer having a molecular weight in the range of from at least about 1000 to not more than about 6000, the molar ratio of (A):(B) being from about 6:1 to about 1:1, the amount of (C) being from about 0.2% to about 5% by weight based on the weight of (A) plus (B), and the amount of (D) being from about 0.25% to not more than 10% by weight based on the sum of the weights of (A) plus (B) plus (C), polymerizing said polymerization reaction mixture at a temperature of from 35° to 50° C. until the monomers have gelled and then raising the temperature to 50° to 60° C. and completing the polymerization at the latter temperature and thereby obtaining the hydrophilic copolymer.
Claim 2
Dependent Claim
166 words
A hydrophilic copolymer obtained by forming a polymerization reaction mixture consisting essentially of (A) N-vinyl-2-pyrrolidone, (B) methyl methacrylate, (C) at least one cross-linking agent having at least two olefinic double bonds in its molecule and (D) an ethylene oxide-propylene oxide block copolymer having a molecular weight in the range of from at least about 1000 to not more than about 6000, the molar ratio of (A):(B) being from about 6:1 to about 1:1, the amount of (C) being from about 0.2% to about 5% by weight based on the weight of (A) plus (B), and the amount of (D) being from about 0.25% to not more than 10% by weight based on the sum of the weights of (A) plus (B) plus (C), polymerizing said polymerization reaction mixture at a temperature of from 35° to 50° C. until the monomers have gelled and then raising the temperature to 50° to 60° C. and completing the polymerization at the latter temperature and thereby obtaining the hydrophilic copolymer.
Claim 3
Dependent Claim
21 words
A hydrophilic copolymer according to claim 1, in which the molar ratio of (A):(B) is from about 4:1 to about 1:1.
Claim 4
Dependent Claim
13 words
A hydrophilic copolymer according to claim 2, in which (C) is allyl methacrylate.
Claim 5
Dependent Claim
33 words
A hydrophilic copolymer according to claim 3, in which (D) is present in an amount of not more than about 5% by weight based on the weight of (A) plus (B) plus (C).
Claim 6
Dependent Claim
20 words
A hydrophilic copolymer according to claim 4, in which (D) has a molecular weight in the range 1,500 to 5,000.
Claim 7
Dependent Claim
21 words
A hydrophilic copolymer according to claim 5, in which (D) has a molecular weight of from about 3,000 to about 4,000.
Claim 8
Dependent Claim
31 words
A hydrophilic copolymer according to claim 6, in which the amount of (D) is from about 0.5% to about 3%, based on the total weight of (A) plus (B) plus (C).
Claim 9
Dependent Claim
27 words
A hydrophilic copolymer according to claim 2, in which (C) is allyl methacrylate, in an amount of not more than 2% by weight of (A) plus (B).
Claim 10
Dependent Claim
12 words
A contact lens made from the hydrophilic copolymer claimed in claim 7.
Claim 11
Dependent Claim
60 words
A hydrophilic copolymer according to claim 1 in which the polymerizing step is carried out by adding to the polymerization reaction mixture from 0.01% to 0.10% by weight, based on the weight of (A) plus (B) plus (C), of a polymerization initiator, then polymerizing the polymerization reaction mixture under an inert gas atmosphere, or in vacuo, until polymerization is completed.
Claim 12
Dependent Claim
29 words
A hydrophilic copolymer according to claim 1, in which (C) is selected from the group consisting of allyl methacrylate, divinyl benzene, ethylene glycol dimethacrylate and diethylene glycol bis(allyl carbonate).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |